Upper airway obstruction is a common problem in pediatric patients. There were a few reports that airway obstruction caused by redundant arytenoid mucosa. The etiology of redundant arytenoid remains unknown. Redundant arytenoid mucosa is diagnosed endoscopically when one or both arytenoids anteriorly displace into the glottic inlet upon inspiration. The common symptoms are hoarseness, stridor, snoring or dyspnea on exertion. These symptoms are similar to croup and they can be easily misdiagnosed as croup. We experienced rare case of upper airway obstruction caused by redundancy of arytenoid mucosa and report it with review of literatures.